The Ketamine is in a cream. And yes, at first it took a LOT for me to manage to touch my foot. But bear in mind that desensitization is also incredibly important for improvement in the condition. There are articles about it on some of the RSD/CRPS websites. It is through desensitization that I have been able to weight bear on my foot, wear a super fluffy, loose, chenille sock, etc.
At first I could barely apply it, so I only did it very lightly on the worst areas. Then my doc had me get lidocaine cream and apply that first and it helped a lot. You can get that OTC (so even if you can't get the Ketamine, I recommend the lidocaine). Its sold as Anecream 5% (its for hemorrhiods, but that really doesn't matter). Its very lightweight so easy to apply with barely touching. I find it cooling and very lightly relieving.

It is SO important to do things to touch the affected area in just tiny tiny bits with soft things (like cotton balls) for very short periods of time repeatedly every day. Like say, three times each day touch the affected area with a cotton ball for 10 sec. 5 x. After a week, increase it to 10 sec. Do what gets up to the threshold of about to worsen, not what actually flares.
A good PT with experience with CRPS can guide him with desensitization.